"""
Unopinionated display configuration.
"""
import locale
import sys

from pandas._config import config as cf

# -----------------------------------------------------------------------------
# Global formatting options
_initial_defencoding = None


def detect_console_encoding():
    """
    Try to find the most capable encoding supported by the console.
    slightly modified from the way IPython handles the same issue.
    """
    global _initial_defencoding

    encoding = None
    try:
        encoding = sys.stdout.encoding or sys.stdin.encoding
    except (AttributeError, IOError):
        pass

    # try again for something better
    if not encoding or 'ascii' in encoding.lower():
        try:
            encoding = locale.getpreferredencoding()
        except Exception:
            pass

    # when all else fails. this will usually be "ascii"
    if not encoding or 'ascii' in encoding.lower():
        encoding = sys.getdefaultencoding()

    # GH#3360, save the reported defencoding at import time
    # MPL backends may change it. Make available for debugging.
    if not _initial_defencoding:
        _initial_defencoding = sys.getdefaultencoding()

    return encoding


pc_encoding_doc = """
: str/unicode
    Defaults to the detected encoding of the console.
    Specifies the encoding to be used for strings returned by to_string,
    these are generally strings meant to be displayed on the console.
"""

with cf.config_prefix('display'):
    cf.register_option('encoding', detect_console_encoding(), pc_encoding_doc,
                       validator=cf.is_text)
